Ramesh: A discussion of proportion absent one of war aims is incomplete.
I reject the usual definition that “anticipated goods of waging war must be commensurate to its expected harms” because neither the benefits or costs of war are easily discernible at its outset. A definition that empirical cannot be of any practical use. As well if it means “use enough force to get the job done” it is but a truism. And clearly that point has not been reached yet.
Proportionality in war in its Jus ad Bellum sense is only workable when there is a shared framework between the combatants, a sense that there will eventually be a postwar period and that whatever is being disputed is not important enough to go to the point of total war. For non-revisionist powers this is feasible, since both sides agree that whatever they are fighting over is not so important that they will seek to annihilate each other. In short, they don’t fight total wars over limited objectives.
But by the same token you should not fight limited war over total objectives, nor when objectives are asymmetric. We faced that disconnect in Vietnam — we limited the war we fought because we pursued limited objectives. The North Vietnamese fought an unlimited war with revisionist objectives (conquest of the South). We figured in time they would give up because we could not be defeated. They would not give up because we chose not to defeat them, and they knew it.
In the current conflict the objectives are symmetrical. Hamas seeks to destroy Israel. They can’t, but they very much want to. Israel wants, or should want, to destroy Hamas. These revisionist objectives should determine the character of the war, and they do not argue for half-measures. But that does not require Israel to use scorched-earth tactics, nor have they. Israel has limited its conduct of war (c.f. Jus in Bello) in the sense that it goes to great pains to target only military targets, something Hamas cannot be bothered to do apparently. These targets are subjected to the full force that Israel can bring to bear. This what U.N. General Secretary Ban Ki-moon has called “excessive force” but it is really effective force, designed for maximum military impact with the least effect on civilians. Hamas’s practice of basing its forces in populated areas is a conscious tactic to increase civilian casualties for which they should be held responsible, not Israel.
Proportionality can have a practical utility among status-quo powers who understand that there are more important issues at stake than the conflict they may be involved in. But it has no particular role when the fight is to the death, as this fight really ought to be.